package net;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;

/**
 * Creat by TanLei
 * Description:
 * User:86183
 * Date:2022-06-16
 * Time:13:51
 */
public class UdpEchoServer {
    private DatagramSocket socket = null;

    public UdpEchoServer(int port) throws SocketException {
        socket = new DatagramSocket(port);
    }

    public void start() throws IOException {
        System.out.println("服务器启动！");
        while (true) {
            DatagramPacket requstPacket = new DatagramPacket(new byte[4096], 4096);
            socket.receive(requstPacket);

            String request = new String(requstPacket.getData(), 0, requstPacket.getLength());
            String response = process(request);

            DatagramPacket responsePacket = new DatagramPacket(response.getBytes(), response.getBytes().length,
                    requstPacket.getSocketAddress());
            socket.send(responsePacket);
            System.out.printf("[%s:%d] req: %s;resp: %s\n", requstPacket.getAddress().toString(), requstPacket.getPort(), request, response);

        }
    }

    public String process(String request) {
        return request;
    }

    public static void main(String[] args) throws IOException {
        UdpEchoServer server = new UdpEchoServer(9090);
        server.start();
    }
}
